Technical Field
The present invention relates to a reticle pod. More particularly, the present invention relates to a dual containment EUV reticle pod.
Description of Related Art
In recent years, the semiconductor manufacturing technology advances rapidly, in which the photolithography process plays an important role. Generally, photolithography involves fabricating a light permeable reticle with desired pattern and projecting the pattern onto a wafer having photoresist by exposing to a light source. After etching and other process steps, the desired pattern is formed on the wafer.
During the photolithography process, any particles attached on the wafer, such as dust or organic matters, would deteriorate the image quality projected onto the wafer. However, the industry trend is towards the production of chips that are smaller in size and with a higher logic density. The wavelength of the light source used by the photolithography equipment is narrowed down to the range of extreme ultraviolet light (EUV). As a result, the manufacturers must set a stricter standard for particle number, particle size, and the internal cleanliness of the reticle pod.
Generally, the reticle pods used in the semiconductor process are made of anti-contaminate material to keep the reticle clean. The reticle pods or semiconductor component containers also should comply with the miniature cleanroom requirements of Standard Mechanical Interface (SMIF) technology. However, even in a controlled environment, the reticle pods are still subjected to particle contamination resulting from the fluctuation of air pressure or the air disturbance by the movement of the container. The particles can be carried into the region between the reticle and the container and even onto the reticle, so the reticle pods still couldn't provide sufficient protection to the reticle from particle contamination.